There's no rule changing. Another thing, son got mad rappers with co-writing credits on individual songs. They could've said nah say it like this or that sounds fire. Some could've written the entire thing too. We don't know who exactly contributed what. The Dre comparison is an interesting one cuz it seems like most if not all of us get the impression that all Dre is doing is tweaking a little and not having much of a role in the creative process. The impression I have of Kanye is that he's involved in the whole process. When it comes to Dre, it's like he's more or less making things sound better through mixing mostly. The same impression is what people have of the lyrics with Dre as well. The ghostwriting or producing sentiment ya have is due to the idea that's engrained in hip hop which is being entirely individual and either writing or producing your own ish unlike other genres.
I understand when dudes say stuff like this, but it's not like Kanye really impressed all that much on this album nor does it sound like any other rapper in terms of style. Much of it ain't really exploring anything crazy creatively nor is he flowing crazy on anything. Nobody is being blown away, by much of the lyrics on the album.